/* Cydia Substrate - Powerful Code Insertion Platform
 * Copyright (C) 2008-2011  Jay Freeman (saurik)
 */

/* GNU Lesser General Public License, Version 3 {{{ */
/*
 * Substrate is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * Substrate is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 **/
/* }}} */

#include "CydiaSubstrate.h"
#include "PosixMemory.h"
#include "Log.h"

#include <sys/mman.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>

extern "C" SubstrateMemoryRef SubstrateMemoryCreate(
		SubstrateAllocatorRef allocator, SubstrateProcessRef process,
		void *data, size_t size) {
	if (allocator != NULL) {
		MSLog(MSLogLevelError, "MS:Error:allocator != NULL");
		return NULL;
	}

	if (size == 0)
		return NULL;

	int page(getpagesize());

	uintptr_t base(reinterpret_cast<uintptr_t>(data) / page * page);
	size_t width(
			((reinterpret_cast<uintptr_t>(data) + size - 1) / page + 1) * page
					- base);
	void *address(reinterpret_cast<void *>(base));

	if (mprotect(address, width, PROT_READ | PROT_WRITE | PROT_EXEC) == -1) {
		MSLog(MSLogLevelError, "MS:Error:mprotect() = %d", errno);
		return NULL;
	}

	return new SubstrateMemory(address, width);
}

extern "C" void SubstrateMemoryRelease(SubstrateMemoryRef memory) {
	if (mprotect(memory->address_, memory->width_,
			PROT_READ | PROT_WRITE | PROT_EXEC) == -1)
		MSLog(MSLogLevelError, "MS:Error:mprotect() = %d", errno);

	__clear_cache(reinterpret_cast<char *>(memory->address_),
			reinterpret_cast<char *>(memory->address_) + memory->width_);

	delete memory;
}
